The present disclosure relates to a light-emitting device that does not include an electrode on a light emission surface and a display including the light-emitting device in each pixel.
In recent years, LEDs (Light Emitting Diodes) have been used in various devices such as backlights of liquid crystal displays, display panels of LED displays and lighting fixtures. Accordingly, cost reduction in LEDs is strongly desired. To reduce the cost of the LEDs, for example, an improvement in productivity, selection of low-cost materials and the like are necessary.
For example, to improve productivity, typically, a chip size is reduced to produce a large number of LEDs from one wafer. In recent years, the chip size is extremely small, for example, 20 μm, and it is difficult to handle a single LED chip. Therefore, it is not realistic to mount each LED chip on a circuit board with use of a mounter.
Therefore, as described in Japanese Unexamined Patent Application Publication No. 2002-182580, for example, instead of mounting with use of the mounter, enlarged transfer which will be described below has been performed. First, a supporting wafer including an adhesive layer on a surface thereof is prepared. Next, the surface where the adhesive layer is provided of the supporting wafer is brought into contact with a surface on an LED side of a wafer formed by forming a plurality of LEDs in a matrix on a substrate, and then LEDs are separated from the wafer at predetermined intervals by laser lift-off to transfer the LEDs to the supporting wafer. Accordingly, the arrangement pitch of the LEDs is sparse. Next, a circuit board (a glass substrate) in which connection electrodes are formed with a pitch equal to the sparse arrangement pitch of the LEDs is prepared, and the LEDs adhered to the supporting wafer are transferred to the circuit board. Thus, a mounting board formed by mounting the LEDs on the circuit board is allowed to be formed.